WordUp - description from Softdepia.com:

WordUp combines the challenge of word games with the fun of computer entertainments. Make as many 3 - 9 letter words as you can by clicking on Letter Tiles adjacent or diagonal to each other. The bigger the word, the bigger you score - and the longer you get to stay in the game.
In Arcade mode, you need to achieve certain threshold scores in order to level up and stay in the game. You can make as many words as you like - but you have to get to your points goals before time runs out! Enjoy 3 great WordUp game modes -- action, arcade and "vanilla swirl" -- find the one you love the most. Over 1,000 special words trigger hilarious bonus sound effects. Worldwide high scores separate the super-spellers from the so-so. In Strategy or Vanilla mode, you have unlimited time to achieve certain threshold scores in order to level up and stay in the game. But you must get it done in 15 words or less in each level - so take your time and go for big words!
Either way - as levels progress, you need to stay on your toes as your spelling prowess is put to the test.

WordUp is a "Free to try" program. You can download and try it for an evaluation period.